We propose to continue a northern sky program using high resolution, moderate S/N spectra to discover the chemically oldest stars - ultra metal-poor dwarfs and giants drawn from the Hamburg/ESO and SEGUE surveys. With these data we seek to (1) discover more stars with [Fe/H] < -4.0 (only three of which are known and all of which our group has discovered) to constrain the nature of the first stars; (2) measure the Li abundance for more stars with [Fe/H] < -4.0, to investigate further the non-detection on this element in the subgiant HE1327-2326 ([Fe/H] = -5.4) and its implication for Big Bang Nucleosynthesis; and (3) discover further r-process enhanced metal-poor stars with detectable Th and U, for cosmo-chronometric age determinations.